2018 was an extraordinary year in terms of solar irradiation for several Northern European countries, with more than 10% sunshine than the long-term average (P50) in many places. However, Southern European countries had a much darker year with irradiation values up to 7% lower than the average.
An increase or decrease in solar index also corresponds to an increase or decrease of the solar parks production for the considered period with respect to the expected P50 values as calculated in the business model. Solar asset owners in Northern European countries experienced an extraordinary year in their revenues during 2018 due to the very high solar irradiation values.
The previous years had a completely different pattern. For example, 2017 was a very sunny year for Southern European countries while Northern latitudes had less sunshine than average. This pattern was reversed in 2018 where most of the Northern European countries experienced an unprecedentedly high solar irradiation throughout the year.